Feature Sensitive Three-Dimensional Point Cloud Simplification using Support Vector Regression

Contemporary three-dimensional (3D) scanning devices are characterized by high speed and resolution. They provide dense point clouds that contain abundant data about scanned objects and require computationally intensive and time consuming processing. On the other hand, point clouds usually contain a large amount of redundant data that carry little or no additional information about scanned object geometry. To facilitate further analysis and extraction of relevant information from point cloud, as well as faster transfer of data between different computational devices, it is rational to carry out its simplification at an early stage of the processing. However, the reduction of data during simplification has to ensure high level of information contents preservation; simplification has to be feature sensitive. In this paper we propose a method for feature sensitive simplification of 3D point clouds that is based on ε insensitive support vector regression (ε-SVR). The proposed method is intended for structured point clouds. It exploits the flatness property of ε-SVR for effective recognition of points in high curvature areas of scanned lines. The points from these areas are kept in simplified point cloud along with a reduced number of points from flat areas. In addition, the proposed method effectively detects the points in the vicinity of sharp edges without additional processing. Proposed simplification method is experimentally verified using three real world case studies. To estimate the quality of the simplification, we employ non-uniform rational b-splines fitting to initial and reduced scan lines

UPORABA UMJETNIH NEURONSKIH MREŽA U PREDVIĐANJU PROFESIONALNIH KRETANJA MATURANATA

Aim of this paper is to examine the possibility of predicting professional choice of secondary school graduates by using artificial neural network for the needs of enrolment policy planning at the Faculty of Mechanical Engineering in Belgrade. The problem of professional choices prediction for graduates has been carried out on the sample of 119 graduates from two Belgrade vocational schools. Factors influencing professional choice of secondary school students grouped in twelve input variables proved to be as suitable for predicting professional movements of graduates. Results of this research represent the base for the further researches aiming to improve the Faculty enrolment policy.Svrha ovog rada je istražiti mogućnosti predviđanja izbora profesije maturanata uporabom umjetnih neuronskih mreža zbog potrebe planiranja upisne politike Strojarskog fakulteta u Beogradu. Istraživanje predviđanja odabira profesije provedeno je na uzorku od 119 maturanata dvije beogradske strukovne srednje škole. Svrstavanje čimbenika koji utječu na izbor profesije kod srednjoškolaca u dvanaest ulaznih varijabli pokazalo se odgovarajućim za predviđanje profesionalnih kretanja maturanata. Rezultati ovog istraživanja predstavljaju osnovu za daljnja istraživanja usmjerena poboljšanju upisne politike Fakulteta

Campylobacter jejuni infection and IgE sensitization in up to 2-year-old infants

© 2015, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved. Background/Aim. The “hygiene hypothesis” addresses the correlation between the occurrence of atopy and the frequency of infections in the earliest age, explaining an increase in the incidence of atopic diseases by living in good, infection-free, hygienic conditions. The aim of our study was to determine the conection between atopy and Campylobacter infection, and to analyze the association between serum concentrations of total IgE and Campylobacter infection in relation to atopy in children up to two years. Methods. A case control study was conducted with the sample of 98 infants of the average age of 8 months. Total serum IgE and Phadiatop infant multi-test were determined on Immunocap-100 (Phadia AB, Uppsala, Sweden). The presence of atopy was determined by detection of serumspecific IgE ≥ 0.35 kUA/L (Phadiatop infant positive) and serum IgM, IgA, IgG levels against C. jejuni were determined by a quantitative immuno-enzyme test-SERION ELISA classic. Results. Total IgE cut-off values ≥ 15 kU/L point to atopy in infants, and tIgE cut-off values ≥ 8.1 kU/L pointed to a C. jejuni infection in infants. Within the group of atopic children, tIgE levels ≥ 29.8 kU/L point to C. jejuni infection, and within the group of non-atopic children, tIgE levels ≥ 5.9 kU/L point to infection. Enteritis is not a predictor of C. jejuni infection, because of a high frequency of asymptomatic cases of infection. The risk factors for C. jejuni infection are age and tIgE, and the protective factors are breastfeeding and atopy. Conclusion. C. jejuni infection increases the total serum IgE level, which is predictive of infection, regardless of the presence of atopy. The presence of symptomatic C. jejuni infection reduces the risk of atopy in a child of the age of 5–24 months by the factor of 10

Intelligent thermopile-based vacuum sensor

We report here the development of a simple and low-cost intelligent vacuum sensor based on multipurpose thermopile MEMS chips. Our devices have a p(+)Si heater and two thermopiles with 30 p(+)Si/Al thermocouples each. Thermal and electrical isolation is provided by a sandwich membrane (residual n-Si and sputtered oxide). The sensor utilizes for its intelligent mode of operation a modified version of an existing processing module we developed for our piezoresistive sensors

Inhibitory effects of medical plants on the Candida albicans and bacterial growth in the oral cavity

In this mini-review, the authors discuss the effects of ethanol extracts, essential oils and cytotoxicity of some medicinal plants and their compounds used in ethno-medicine in different geographic regions worldwide, including Serbia, on the growth, mul­tiplication and pathogenicity of Candida albicans and bacteria that play the main role in the balance of the oral ecosystem. Various medicinal plants, such as Rosmarinus officinalis (Fam. Lamiaceae), Artemisia dracunculus, Artemisia absinthium (Fam. Asteraceae), exist in different geographic regions and continents, as well as in the Balkan region, and among them there are some indigenous species like Hypericum perforatum L. (Fam. Hypericaceae), Urtica dioica L. (U. dioica) (Fam. Urticaceae), Achillea millefolium L. (Fam. Asteraceae), Matricaria chamomilla L. (Fam. Asteraceae), Sambucus nigra L. (Fam. Caprifoliaceae), and Thymus serpyllum L. (Fam. Lamiaceae) with impressive antimicrobial activity against microorganisms originating from the oral cavity

Microstructural characterization and computer simulation of conductivity in Si3N4-TiN composites

Si3N4-TiN ceramics sintered with Y2O3 and Y2O3 + Al2O3 as sintering aids and various content of TiN (0-50 wt.%) were investigated regarding their microstructural and electrical properties. Electroconductive composites were obtained with TiN content higher than 20 vol.%. Computer simulation of conductivity versus concentration of TiN has been done in respect of different models. The influence of dimensionality and type of conductive network on the critical exponent s in the power law, which describes the conductivity of composites, has been discussed. The addition of beta-Si3N4 seeds affected fracture toughness in Si3N4-36 wt.% TiN composites while only a slight change in electroconductivity of the composites was observed at the same time. (C) 2003 Elsevier B.V. All rights reserved

Intelligent thermal vacuum sensors based on multipurpose thermopile MEMS chips

Realization of intelligent thermal vacuum sensors based on multipurpose thermopile micro-electromechanical (MEMS) chips is presented in this work. These vacuum sensors satisfy the main requirements for contemporary sensors, they are cost-effective in both fabrication and operation, and simple to use. Intelligent devices based on two types of thermal sensors, A-type with Al heater, and Ptype with p(+)Si heater, were developed. Both types have two thermopiles with 30 p(+)Si/Al thermocouples each. Thermal and electrical isolation is provided by a sandwich membrane (residual n-Si and sputtered oxide). The intelligent functionality is achieved by using a signal processing unit the authors developed earlier for pressure sensing based on their proprietary Si piezoresistive pressure sensing elements. The main issues which were of key importance for realization of intelligent vacuum sensors are addressed in this work: design and fabrication of the intelligent vacuum sensors, adaptation of the software module, linearization of the input signal using digital signal processing and temperature compensation. A three-udstage test procedure is presented. The A-type sensor, with a thinner membrane, achieved 19 times better thermopile voltage-pressure sensitivity compared with the P-type sensor, with a thicker membrane. Since the estimated noise level of the measuring system is comparable with the useful signal of the Ptype device, the improved voltage-pressure sensitivity provides a better resolution and signal to noise ratio of the intelligent vacuum measuring system